Dihydroxy bile acids and fatty acids were shown to inhibit intestinal water absorption. The goal of the current proposal is to investigate further their effect on intestinal absorption, particularly on fat absorption in states of net fluid secretion and on intestinal transit. Based on currently available data the following hypotheses are developed: 1) Poorly absorbable hydroxy fatty acids and dihydroxy bile acids inhibit absorption of oleic acid. 2) Fatty acids and dihydroxy bile acids stimulate intestinal motility and transit. 3) Dihydroxy bile acids have no effect on intestinal motility in the presence of lecithin. These hypotheses will be tested in human volunteers by intestinal perfusion techniques. The results of these studies are relevant in relation to normal intestinal function and to certain disease states characterized by diarrhea.